1. Lacking brilliance or vitality
   "a dull lacklustre life"
   - lackluster [US], lusterless [N. Amer], lustreless [Brit, Cdn] 
2. Lacking lustre or shine
   "staring with lacklustre eyes"
   - lackluster [US], lusterless [N. Amer], lustreless [Brit, Cdn]

See also: dull, hebetudinous

• cottage cheese
• cottage dweller
• cottage industry
• cottage pie
• cottage pink
• cottage tent
• cottage tulip
• cottager
• cottaging
• cottar
• cotter
• cotter pin
• Cottidae
• cottier
• cotton
• cotton ball
• cotton bollworm
• cotton cake
• cotton candy
• cotton fiber
• cotton fibre
• cotton flannel
• cotton gin
• cotton grass
• cotton mill